Today, the need for proper hygiene, in particular in the form of hand hygiene, is widely acknowledged. For this reason, public or commercial facilities such as washrooms in public buildings, offices, restaurants, airports, hospitals, shopping malls and so on are normally provided with dispensers for various consumable goods, for example paper towels, liquid soap and toilet paper. The purpose is of course to make such consumables easily available to the guests in the washrooms.
Consumables are normally stored in said dispensers, which for this purpose are fixedly located at suitable positions in the washroom. A dispenser can for example be in the form of a holder for paper towels, a holder for toilet paper or a container for liquid soap. Other types of dispensers, for example trash cans, are also used.
The task of checking the level of each consumable, and refilling a dispenser when necessary, i.e. when the level of the consumable is low, or emptying a bin when the level of the consumable is high, is normally assigned to a cleaning staff or a janitor. One problem for a janitor is to know which dispensers that need to be refilled and how much consumable material to bring when servicing an area containing a number of dispensers. Furthermore, from a management point of view, it can be difficult to know in advance how much consumable materials should be ordered and kept in stock. For these reasons, there is a need for dispensers which are arranged for monitoring the actual use of the consumable and for signalling in some suitable manner to a central service office that, for example, a particular dispenser needs refilling. To this end, it is known that a modern dispenser may include one or more sensors which are arranged for detecting the level of the consumable within the dispenser. Generally, such sensors can be arranged for recognizing any condition indicating that the level of a consumable is low, i.e. by detecting that the level of the consumable is below a predetermined threshold value. The sensor in question can for example be based on an infrared sensor which is arranged for detecting when the height of a paper stack, such as a stack of paper towels in a dispenser, falls below a specified low paper threshold. This threshold corresponds to a condition in which the dispenser needs refilling.
There exist also solutions in which a dispenser is arranged for automatically dispensing a consumable. An example is an automatic soap dispenser which is arranged for automatically discharging a small amount of soap when a user holds a hand under an output nozzle of the dispenser. Such a dispenser can be arranged with sensor arrangements which keep track of the number of occasions that the nozzle has been actuated. The number of occasions can then be used for estimating the amount of consumable which has been fed from the dispenser, and consequently also the remaining amount. When a predetermined minimum threshold has been reached, the dispenser can send a signal to a central service office indicating that it needs refilling.
Other types of sensors can for example be based on a light emitting diode and a photodetector which together can be used for detecting the level of a consumable within a dispenser. A further example is a counter device counting the number of turns on a toilet paper dispenser, wherein the accumulated number of turns corresponds to a certain consumption of toilet paper.
As mentioned above, a sensor which is associated with a dispenser for a consumable can be connected to a central service office, i.e. to a central computer server, so that the server is notified when a particular dispenser needs refilling. A notification relating to a dispenser low condition can then be forwarded to members of a cleaning staff, who then has the responsibility of refilling that particular dispenser as soon as possible.
A system for monitoring hygiene applicances is previously known from the patent document US 2011/0163870, which teaches a wireless system for monitoring a number of dispensers. The system comprises a number of sensors which are connected to a hub, i.e. a data collecting unit. The hub is connected to a gateway which communicates, via a cellular network, with a remote server which is associated with a database.
A particular problem which is relevant with regard to a monitoring system of the above-mentioned type is that a system may involve a relatively large number of sensors and data collecting units. This means that the data traffic, i.e. the flow of information related to the consumption of consumables, dispenser operation, visitor counting, etc. between the various units such as the sensors and the data collecting units, can be both intensive and costly, and may also require well-dimensioned and costly server and database systems.
This means that a problem involved with previously known solutions is that they are not always cost-effective with regard to data communication cost and computer infrastructure.